Sanitary frostproof hydrant

ABSTRACT

A hydrant for controlling the flow of water from an underground supply includes drain apparatus for draining the hydrant to prevent frost damage while preventing ground water contamination of potable water from the supply. Water from the supply is admitted by a supply valve to a casing extending from below the frost line to above ground. When the valve is closed, water from within the casing drains through a conduit having an inlet within the casing below the frost line and having an outlet located below the inlet and outside of the casing. The conduit includes a siphon located above both the inlet and outlet, and preferably above ground. The conduit includes an air chamber for maintaining an air gap within the conduit. A check valve is provided to prevent backflow through the conduit from the outlet to the inlet.

Carlson [4 1 Jan. 7, 1975 1 1 SANITARY FROSTPROOF HYDRANT [75] Inventor: Donald E. Carlson, Highland Park,

Ill.

[73] Assignee: Mark Controls Corporation,

Evanston, Ill.

[22] Filed: Oct. 16, 1973 [21] Appl. No.: 406,911

152] U.S. Cl 137/218, 137/151, 137/307,

239/200, 239/574, 239/583 [51] Int. Cl. E03c 1/10, E03b 9/14 [58] Field of Search 137/107, 301604,

Kilayko 137/218 Noland 137/301 X Primary ExaminerRobert S. Ward, Jr. Attorney, Agent, or Firm-Mason, Kolehmainen, Rathburn & Wyss 1571 ABSTRACT A hydrant for controlling the flow of water from an underground supply includes drain apparatus for draining the hydrant to prevent frost damage while preventing ground water contamination of potable water from the supply. Water from the supply is admitted by a supply valve to a casing extending from below the frost line to above ground. When the valve is closed, water from within the casing drains through a conduit having an inlet within the casing below the frost line and having an outlet located below the inlet and outside of the casing. The conduit includes a siphon located above both the inlet and outlet, and preferably above ground. The conduit includes an air chamber for maintaining an air gap within the conduit. A check valve is provided to prevent backflow through the conduit from the outlet to the inlet.

14 Claims, 7 Drawing Figures PATENIEBJAN' 11915 3, 858 593 sum 2 or 2- SANITARY FROSTPROOF HYDRANT The present invention relates to hydrants, such as yard hydrants, and more particularly to an improved sanitary frostproof hydrant.

Hydrants are used for selectively supplying water from an underground water supply. A typical yard hydrant includes a casing adapted to be communicated with the below ground water supply and extending above ground. In regions where low temperatures result in freezing, a supply valve for controlling the entry of water to the casing from the supply is normally located below the frost line and is controlled by means of a handle usually carried on a head assembly mounted above ground on the uppermost part of the casing. In order to drain the casing after use of the hydrant, it is customary for the hydrant to include a drain or weep hole near the bottom of the casing, which weep hole may be communicated with a gravel drain field or the like by means of a short conduit.

Difficulties arise with this conventional arrangement when abnormally high ground water levels are caused by heavy rain, melting snow, flooding or the like. If the ground water level is above the casing weep hole, ground water flows in the reverse direction into the hydrant casing. Should the hydrant be used during such conditions, potable water from the supply is mixed with ground water in the casing. Even if the hydrant is used after the water level recedes, it is possible for contamination to result from residual materials, bacteria or the like remaining in the casing after draining.

An important object of the present invention is to provide an improved hydrant wherein draining after use is achieved without the possibility of reverse flow into the hydrant during high water conditions and regardless of the sequence of the rise and fall of ground water levels. Another object is to provide a drain arrangement wherein contamination, as by bacterial migration, along a continuous water path is prevented.

In brief, the above and other objects and advantages of the present invention are achieved through the provision of a hydrant including a casing extending from below the frost line to an above ground position. Water is selectively supplied from an underground supply to the lower portion of the casing by means of a supply valve. A head assembly is carried by the upper portion of the casing, and a handle supported by the head assembly controls the opening and closing of the supply valve.

In accordance with an important feature of the invention, a drain conduit is provided for draining the interior of the hydrant casing after use. The conduit includes an inlet within the lower portion of the casing and an outlet disposed outside of the casing. The conduit includes a siphon disposed above the inlet and the outlet. In accordance with another feature of the inven tion, the conduit includes a check valve in order positively to prevent backflow through the drain conduit, and further includes an air chamber for continuously maintaining an air gap between the inlet and outlet.

The invention together with the above and other objects and advantages will be more fully understood from the following detailed description of the embodiment of the invention illustrated in the accompanying drawings, wherein:

FIG. I is a fragmentary, side elevational view, partly in section, of a hydrant constructed in accordance with the invention;

FIG. 2 is a fragmentary, enlarged side view of a portion of the hydrant casing, with the casing shown in section taken along the line 2-2 of FIG. 3;

FIG. 3 is a sectional view taken along the line 33 of FIG. 2;

FIG. 4 is a sectional view of the base of the hydrant taken along the line 44 of FIG. 5;

FIG. 5 is a sectional view taken along the line 5-5 of FIG. 4;

FIG. 6 is a view similar to a portion of FIG. 4 and illustrating the supply valve in the open position; and

FIG. 7 is a sectional view taken along the line 7-7 of FIG. 6.

Referring now to the drawings, there is illustrated a yard hydrant constructed in accordance with the principles of the present invention and designated as a whole by the reference numeral 10. In general, the hydrant includes a-hollow casing 12 extending from a supply valve assembly generally designated as 14 located below ground and below the frost line to a head assembly generally designated as 16 disposed at a convenient elevation above ground. An operating handle l8-controls the valve assembly 14 selectively to admit water to the casing 12 and head assembly 16 from a suitable below ground water supply such as water supply pipe 20.

In accordance with important features of the present invention, the hydrant 10 is provided with novel structure for draining water from the casing 12 after use and for preventing contamination of water within the casing by ground water outside of the casing. In order to drain the hydrant 10, there is provided a conduit designated generally by the reference numeral 22 extending from the interior to the exterior of the casing. The conduit includes a siphon portion 24 serving to permit drainage through the conduit 22 while preventing backflow into the casing. In addition, the conduit 22 includes an air chamber 26 providing a continuous air gap in the conduit for the prevention of bacteria migration from the exterior to the interior of the casing 12. Further in accordance with the invention, a check valve generally designated as 28 is associated with the conduit 22 in order further to prevent backflow through the conduit 22.

Proceeding now to a more detailed description of the structure and operation of the hydrant 10, the casing 12 in the illustrated arrangement is in the form of a right circular cylindrical body having upper and lower threaded ends 30 and 32. Preferably the casing is imperforate in order to avoid the expense of passing the conduit 22 through the casing wall. The casing 12 may be of any desired length depending upon the installation, with the lower end 32 of the casing disposed below the frost line and the upper end at any desired height.

Water introduced into-the casing 12 flows through the head assembly 16. Assembly 16 is supported on the upper end 30 of the casing by means of a threaded adapter member 34 and a coupling member 36. The major structural component of the head assembly 16 is a unitary head member 38 provided with a hollow interior flow chamber 40 communicating at one end with the interior of the casing 12 and at the other end with an outlet 42 disposed in a spigot portion 44 of the head member 38.

In order to control the operation of the valve assembly 14, the operating handle 18 is provided. This handle is pivoted by means of a bolt 46 to a support arm portion 48 of the head member 38. The handle is interconnected by a link 50 pivoted on pins 52 and 54 with an adjustable fitting 56. Movement of the handle in an upward direction from the illustrated closed position results in upward movement of the fitting 56 and thus in upward movement of a valve operating plunger 58 coupled to the fitting 56 by means of a connecting shaft 60 and adapter fitting 62. A seal assembly 64 carried by the head member 38 circles the shaft 60 to prevent leakage from the chamber 40. A latch member 66 releasably retains the handle 18 in the illustrated closed position.

Referring now to the valve assembly 14, a valve body 68 is connected by threading to the lower end 32 of the casing 12. As best seen in FIGS. 4-7, the valve body includes a through passage 70 extending between an inlet 72 at its lower end and an outlet 74 at its upper end, the latter opening into'the interior of the casing 12. A valve seat 76 is positioned in the passage 70 below a reciprocal valve member 78 connected to the lower end of the plunger 58. In the position illustrated in FIG. 4, the valve assembly is in the closed position and valve member 78 seals against seat 76. When the plunger is raised, the valve member 78 moves in an upward direction away from the seat 76 to permit fluid to flow from the supply pipe 20 into the casing 12.

More specifically, and as best shown in FIGS. and 7, a pair of flow cavities 80 are provided in the valve body 68 and extend from inlet ports 82 to outlet ports 84 located at axially spaced positions along the passage 70. In the closed position of the valve illustrated in FIG. 4, the valve member 78 not only closes the seat 76, but also overlies the inlet ports 82. When the valve member 78 is raised to the valve open position illustrated in FIGS. 6 and 7, the inlet ports 82 are uncovered and fluid flows through the seat 76, through the inlet ports 82 and the flow cavities 80, and through the outlet ports 84 into the passage 70 and casing 12.

When the valve assembly 14 is opened to supply water from the hydrant 10, the casing 12 fills with water. Upon reclosing of the valve assembly 14, it is desirable to drain water from the casing 12 in order to prevent damage to the hydrant by freezing. In accordance with the present invention, water is drained from the casing 12 by means of the conduit 22.

Water enters the conduit 22 through an inlet passage 86 (FIGS. 4 and 6) formed in the valve body 68. Passage 86 extends from a drain conduit inlet port 88 formed in the wall of the passage 70, and as can be seen from a comparison of FIGS. 4 and 6, the port 88 is closed by the valve member 78 in its open position. As a result, whenwater is flowing through the hydrant 10, diversion of flow through the conduit 22 is prevented. When the valve member 78 is moved to its closed position, the inlet port 88 is opened to the interior of the casing 12.

Conduit 22 also includes an outlet passage 90 (FIG. 4) formed in the valve body 68 and leading from the interior of casing 12 to an outlet fitting 92. As shown in FIG. 1, fitting 92 serves to intercommunicate the outlet passage 90 with an outlet drain tube 94 extending to the exterior of the hydrant 10. In the illustrated arrangement, tube 94 terminates in a gravel drain field 96, although it will be understood that such a drain field may not be necessary depending upon the subsoil composition at the hydrant installation. Tube 94 terminates in an outlet end 100, and preferably this end is below the level of the inlet port 88 of the conduit 22 in order to provide a difference in pressure head between the inlet 88 and outlet thus to promote drainage of the casing 12 through the conduit 22. The outlet end 100 is provided with a strainer 102 to prevent clogging of the tube 94.

In order to avoid the possibility of contamination of the interior of casing 12 due to abnormally high ground water levels, and in accordance with an important feature of the present invention, the conduit 22 is provided with the siphon portion 24, air chamber 26, and check valve 28. More specifically, the inlet passage and outlet passage portions 86 and 92 of the conduit 22 are connected together by means of a first tube 104 forming the up leg of siphon 24, a second tube 106 forming the down leg of siphon 24, and an air chamber and valve housing 108 connected to tubes 104 and 106 and forming the uppermost portion of the siphon 24.

As can be seen in FIGS. 1 and 2, tube 104 extends upwardly from the valve body 68 within the casing 12 to a region above ground where it enters the housing 108 through a bottom wall 110. Within the housing 108 the tube extends further upwardly to a location near the top of a cylindrical, closed top wall 112 of the housing 108 where it terminates in an upper end 114. Conversely, tube 106 extends upwardly from the valve body 68 and terminates in an upper end 116 located at the bottom of the housing 108 and thus below the upper end 114 of the up leg tube 104.

The arrangement of tubes 104 and 106 relative to the housing 108 maintains an air gap between the inlet 88 and outlet 100 of the conduit 22 during draining of the casing 12. More specifically, during the draining process water flows from the casing 12 in to the up leg 104 and out of the upper end 114 thereof into the housing 108. From the housing 108 the water flows through the down leg tube 106 and out of the hydrant 10. Air remains trapped within the housing 108, and, in the event of high ground water and incomplete drainage of the casing 12, prevents the existence of an uninterrupted fluid connection between the casing and exterior ground water which might otherwise make it possible for bacterial contamination of potable water within the casing 12.

In accordance with another feature of the invention, backtlow through the conduit 22 due to pressures resulting from abnormal water levels is prevented. For this purpose, the check valve 28 is provided. As illustrated' in FIG. 2, the check valve 28 includes a valve member or ball 118 cooperating with a valve seat 120 formed by the end of a length of resilient tube 122 telescoped over the end 114 of the tube 104. The ball 1 18 is formed of a heavier than air and heavier than water material, such as steel or other metal, and as a result under all conditions is gravity-biased to a closed position. In addition, the diameters of the tube 122 and wall 112 are chosen relative to the diameter of the ball 118 in order to capture the ball in the region above the valve seat 120.

As water flows through conduit 22 during draining of the casing 12, the valve ball 118 is lifted from its seat by flow through the tube 104 and water is permitted to enter the housing 108 and be drained from the hydrant 10. However, should a water table condition exist which would tend to cause reverse flow through the conduit 22, the valve ball 118 remains firmly seated against the valve seat 120 to prevent such reverse flow. The valve ball 118 sealing against the seat 120 also serves to prevent the evacuation of air from within the housing 108 during reverse pressure conditions.

In accordance with yet another feature of the inven tion, the tubes 104 and 106 in combination with the housing 108 provides a siphon through which water is drained from the casing 12 to the drain field 96. Under normal circumstances, after use of the hydrant, the entire casing 12 is filled with water to a level above the uppermost end of the siphon 24. As a result, after the supply valve assembly 14 is closed, flow is initiated through the siphon 24 due to the pressure differential existing between the water head within the casing 12 and the pressure existing at the outlet end 100 of the drain tube 94. Once flow through the siphon 24 is initiated, it continues until the casing 12 is fully drained, assuming that the ground water level is below the level of the inlet port 88 of the conduit 22.

The up leg and down leg tubes 104 and 106 may be formed of any desired material such as a metal or plastic material. If the tubes have insufficient rigidity to support the housing 108 in the illustrated position, a retaining clip 124 as illustrated in FIGS. 2 and 3 may be provided in order to hold the housing 108 to the side of the casing 12 and out of the path of the plunger 58.

As illustrated in FIG. 1, the spigot portion 44 of the head assembly 16 is provided with a vacuum breaker or backflow preventer device 126. Thisdevice may be of the type disclosed in my copending US. Pat. application Ser. No. 397,828, filed Sept. 7, 1973, executed by me on Sept. 12, 1973 and entitled BACKFLOW PRE- VENTER. In general, the function of the backflow preventer 126 is to prevent reverse flow from a hose or the like connected to the outlet of the hydrant into the hydrant. it is becoming common for the use of such backflow preventers to be required by governmental codes, and one advantage of the present invention is that it permits draining of the hydrant whether or not a backflow preventer is used, and regardless of whether a hose or other equipment is coupled to the outlet 42.

In order to admit air to the interior of the casing 12 for drainage of the casing, there is provided a conventional ball check valve 128. This valve may be .located in any desired position and as illustrated is inserted into the wall of the head member 38 in a relatively protected position under the handle 18.

The operation of the hydrant 10 will be apparent to those skilled in the art in light of the preceding detailed description. Under normal conditions, the water table is well below the drain field 96. After use of the hydrant 10 when the valve 14 is closed, the water pressure head existing within the casing 12 causes evacuation of the casing. More specifically, the ball check valve 128 opens due to negative pressure within chamber 40 to admit air to the casing 12. Water flows from the casing 12 through the conduit 22 and into the drain field 96 thus emptying the hydrant and preventing subsequent damage due to freezing.

During abnormal conditions, ground water may rise to a level above the inlet 88 of the conduit 22. Due to the provision of the siphon 24, it is not possible for ground water to flow in the reverse direction into the empty casing 12 under this condition.

If the hydrant is used with ground water at a level above the inlet 88, when the valve 14 is closed the easing drains through the conduit 22 until the level of water within the casing is substantially equal to the ground water level. When flow stops, the siphon 24 remains filled with water. However, due to the provision of the air gap within the air chamber 26, it is not possible for contaminants to travel through a continuous water path between the outlet and the inlet 88 of the conduit 22. Moreover, even if the ground water level rises at this time, the check valve 28 prevents reverse flow. The check valve 28 also prevents the air tapped within the air chamber 26 from being expelled through the up leg tube 104 and into the casing 12.

In accordance with theinvention the uppermost part of the siphon 24 is located above ground level, so that the entire conduit 22 is not submerged except in extremely unusual conditions. Even in such conditions, however contamination of the interior of the casing 12 does not take place. More specifically, regardless of the water level, the check valve 28 prevents any reverse flow through the conduit 22, and the air chamber 26 also prevents contamination by migration.

Although the invention has been described with reference to the details of the illustrated embodiment, it should be understood that such details are not intended to limit the scope of the invention as defined in the following claims.

What is claimed and desired to be secured by Letters Patent of the United States is:

l. A hydrant for controlling the flow of water from an underground supply comprising:

casing means having a lower portion adapted to extend below the frost line and an upper portion adapted to be located above ground;

valve means for controlling the entry of water from the supply into said casing means;

head means connected to said upper portion forthe delivery of water from said casing;

handle means supported by said head means and coupled to said valve means for opening and closing said valve means;

and the improvement comprising:

conduit means for draining said casing means and having an inlet in the lower portion of said casing means;

said conduit means having an outlet adapted to be located outside of said casing means; and

check valve means in said conduit means for permitting flow from the inlet to the outlet and for preventing flow from the outlet to the inlet.

2. A hydrant as claimed inclaim 1, further comprising a siphon formed bya portion of said conduit means between the inlet and the outlet, said siphon extending above the inlet and the outlet.

3. A hydrant for controlling the flow of water from an underground supply comprising:

casing means having a lower portion adapted to extend below the frost line and an upper portion adapted to be located above ground;

valve means for controlling the entry of water from the supply into said casing means;

head means connected to said upper portion for the delivery of water from said casing;

handle means supported by said head means and coupled to said valve means for opening and closing said valve means;

and the improvement comprising:

conduit means for draining said casing means and having an inlet in the lower portion of said casing means;

said conduit means having an outlet adapted to be located outside of said casing means; and

means in said conduit means for maintaining an air gap between said inlet and outlet.

4. The hydrant of claim 3, further comprising:

a siphon formed by a portion of said conduit means between the inlet and the outlet, said siphon extending above the inlet and the outlet.

5. The hydrant of claim 3, further comprising:

check valve means in said conduit means for permitting flow from the inlet to the outlet and for preventing flow from the outlet to the inlet.

6. The hydrant of claim 5, further comprising:

a siphon formed by a portion of said conduit means between the inlet and the outlet, said siphon extending above the inlet and the outlet.

7. Apparatus for draining water from the below ground and the below frost line portion of a hydrant casing, said apparatus comprising:

conduit means having an inlet within said casing portion and an outlet outside said casing portion; said conduit means including a first tube communicating with said inlet and extending upwardly within 8 said casing, a housing defining an air chamber, said first tube terminating at an upper end within said chamber, a second tube extending downward from said housing within said casing and communicating with said outlet, said second tube including an upper end within said chamber; and a siphon formed by said conduit means; the upper portion of.

said siphon being above said inlet and said outlet.

8. The apparatus of claim 7, said siphon being located inside the casing. I

9. The apparatus of claim 7, said uppermost portion being above ground.

10. The apparatus of claim 7, a supply valve including a valve member movable between closed and open positions to control the entry of water from the supply to the casing, said valve member closing said inlet in its open position.

11. The apparatus of claim 7, the upper end of the first tube being above the upper end of said second tube.

12. The apparatus of claim 11, a check valve in said conduit means for preventing flow from said outlet to said inlet.

13. The apparatus of claim 12, said check valve comprising a valve member engageable with the upper end of said first tube.

14. The apparatus of claim 13, said chamber comprising said uppermost portion of said siphon. 

1. A hydrant for controlling the flow of water from an underground supply comprising: casing means having a lower portion adapted to extend below the frost line and an upper portion adapted to be located above ground; valve means for controlling the entry of water from the supply into said casing means; head means connected to said upper portion for the delivery of water from said casing; handle means supported by said head means and coupled to said valve means for opening and closing said valve means; and the improvement comprising: conduit means for draining said casing means and having an inlet in the lower portion of said casing means; said conduit means having an outlet adapted to be located outside of said casing means; and check valve means in said conduit means for permitting flow from the inlet to the outlet and for preventing flow from the outlet to the inlet.
 2. A hydrant as claimed in claim 1, further comprising a siphon formed by a portion of said conduit means between the inlet and the outlet, said siphon extending above the inlet and the outlet.
 3. A hydrant for controlling the flow of water from an underground supply comprising: casing means having a lower portion adapted to extend below the frost line and an upper portion adapted to be located above ground; valve means for controlling the entry of water from the supply into said casing means; head means connected to said upper portion for the delivery of water from said casing; handle means supported by said head means and coupled to said valve means for opening and closing said valve means; and the improvement comprising: conduit means for draining said casing means and having an inlet in the lower portion of said casing means; said conduit means having an outlet adapted to be located outside of said casing means; and means in said conduit means for maintaining an air gap between said inlet and outlet.
 4. The hydrant of claim 3, further comprising: a siphon formed by a portion of said conduit means between the inlet and the outlet, said siphon extending above the inlet and the outlet.
 5. The hydrant of claim 3, further comprising: check valve means in said conduit means for permitting flow from the inlet to the outlet and for preventing flow from the outlet to the inlet.
 6. The hydrant of claim 5, further comprising: a siphon formed by a portion of said conduit means between the inlet and the outlet, said siphon extending above the inlet and the outlet.
 7. Apparatus for draining water from the below ground and the below frost line portion of a hydrant casing, said apparatus comprising: conduit means having an inlet within said casing portion and an outlet outside said casing portion; said conduit means including a first tube communicating with said inlet and extending upwardly within said casing, a housing defining an air chamber, said first tube terminating at an upper end within said chamber, a second tube extending downward from said housing within said casing and communicating with said outlet, said second tube including an upper end within said chamber; and a siphon formed by said conduit means; the upper portion of said siphon being above said inlet and said outlet.
 8. The apparatus of claim 7, said siphon being located inside the casing.
 9. The apparatus of claim 7, said uppermost portion being above ground.
 10. The apparatus of claim 7, a supply valve including a valve member movable between closed and open positions to control the entrY of water from the supply to the casing, said valve member closing said inlet in its open position.
 11. The apparatus of claim 7, the upper end of the first tube being above the upper end of said second tube.
 12. The apparatus of claim 11, a check valve in said conduit means for preventing flow from said outlet to said inlet.
 13. The apparatus of claim 12, said check valve comprising a valve member engageable with the upper end of said first tube.
 14. The apparatus of claim 13, said chamber comprising said uppermost portion of said siphon. 